One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4,6,8)(5,9,10,7)(12,16)(14,21)(17,22)(18,23)(20,25)(24,26)(3,5,6,10)(4,7,8,9)(11,12,14,16,15,18,21,23)(13,17,20,22,19,24,25,26)(11,13)(12,17)(14,20)(15,19)(16,22)(18,24)(21,25)(23,26) involution — undirected(13,19)(17,24)(20,25)(22,26) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.